PHMP

• Human parasitology is the study of those organismis which parasitize humans
• Human parasitology, an important part of parasitology, study the medical parasites including their morphology, life cycle, the relationship with host and environment
• Parasitic infection /or parasitic diseases are still one of the important problems in public health in our country
• Parasite


  An organism which has become adapted to living on or in some other organism, the host, which is usually larger than itself
• Parasitism


  A relationship between two species where member of one species (smaller, called parasite) derived food and shelter from member of another species (larger, called host)
• Types of Parasites


  • Obligatory
  • Facultative
  • Endoparasite
  • Ectoparasite
  • Permanent
  • Temporary
  • Microparasite
  • Macroparasite
  • Extracellular
  • Intracellular
  • Proliferous
  • Accidental
• Types of Hosts


  • Definitive
  • Intermediate
  • Reservoir
  • Vector (Biological & Mechanical)
  • Carrier
  • Accidental
• Host Selection


  • Monoxenous (single host)
  • Oligoxenous (small range of hosts)
  • Polyxenous (many suitable hosts)
• Types of Parasitic Life Cycle

  • Simple or Direct
  • Complex or Indirect
• Stages Involved in Parasitic Life Cycle

  • Infective
  • Diagnostic
• Sources of Infection


  • Soil
  • Water
  • Food
  • Direct Contact
• Taxonomic classification is a hierarchy of biological classification from Kingdom to Species
• Taxonomic Kingdoms of Life

  • Prokaryotic (Bacteria and blue-green algae)
  • Eukaryotic (Simple multicells or unicells)
• Eukaryotic Kingdoms


  • Protista
  • Plantae
  • Fungi
  • Animalia
• Animal Kingdom Classifications

  • Unicellular Animals (Protozoa)
  • Multicellular Animals (Metazoa)
• Protozoan Taxonomic Classifications

  • Sarcodina
  • Mastigophora
  • Ciliophora
  • Apicomplexa
• Helminth Taxonomic Classifications

  • Platyhelminths (flatworms)
  • Nematodes (roundworms)
  • Cestodes (tapeworms)
  • Trematodes (flukes)
• Categories of Amoeba According to Residency


  • Intraintestinal
  • Extraintestinal
• Categories of Flagellates According to Residency


  • Intraintestinal
  • Hemoflagellates
• Categories of Sporozoa According to Residency


  • Intraintestinal
  • Extraintestinal
• Categories of Nematodes According to Residency


  • Intestinal Species
  • Intestinal-Tissue
  • Lymphatic-Tissue (Vector-dependent)
• Categories of Trematodes According to Residency


  • Intestinal Species
  • Liver Species
  • Lung Specie
  • Blood Specie
• Categories of Cestodes According to Residency

  • Intestinal Species
  • Liver/Lung Specie
• Protozoan Parasites


  Consist of a single "cell-like unit" which is morphologically and functionally complete and can perform all functions of life
• Protozoan Parasites


  • Reproduce sexually & asexually
• Amoebas


  Unicellular membrane bound organisms that have the ability to change their shape
• Amoeba Life Cycle


  1. Mature cysts ingested (Infective Stage)

  2. Excystation (Trophozoites)

  3. Multiplication

  4. Noninvasive Colonization

  5. Intestinal Disease

  6. Extraintestinal Disease

  7. Cysts and trophozoites passed in feces (Diagnostic Stage)
• Entamoeba histolytica Trophozoite


  • Motility: Progressive, finger-like pseudopodia
  • Number of nuclei: 1
  • Cytoplasmic inclusions: Ingested RBC
• Entamoeba histolytica Cyst


  • Shape: Spherical to round
  • Number of nuclei: 1-4
  • Cytoplasmic inclusions: Chromatid bars, rounded ends and diffuse glycogen mass
• Other Common Amoeba Species

  • Entamoeba coli
  • Entamoeba polecki
  • Entamoebanana
  • Iodamoeba butschlii
  • Entamoeba gingivalis
  • Entamoeba hartmanni
• Naegleria fowleri Trophozoite


  • Motility: Sluglike, blunt pseudopods
  • Number of nuclei: 1
  • Cytoplasmic inclusions: Leukocytes and few lymphocytes
• Naegleria fowleri Cyst


  • Shape: Spherical
  • Number of nuclei: 1
  • Cytoplasmic inclusions: Dense cell wall
• Naegleria fowleri Flagellate


  • Motility: Jerky or spinning
  • Number of nuclei: 1
  • Cytoplasmic inclusions: Bacteria and other cells
• Naegleria fowleri


  • Considered as the only amoeba that has three morphological forms in its life cycle that infects humans
• Acanthamoeba species Trophozoite


  • Motility: Sluggish, spine-like pseudopods
  • Number of nuclei: 1
  • Cytoplasmic inclusions: Leukocytes and few lymphocytes
• Acanthamoeba species Cyst


  • Shape: Roundish with ragged edges
  • Number of nuclei: 1
  • Cytoplasmic inclusions: Bacteria or fungi
  • Has a characteristic of double cell wall (Inner-smooth, Outer-ragged)
• Naegleria fowleri and Acanthamoeba species are typically found in warm bodies of water, they are pathogenic and produce variety of severe diseases particularly in the brain and cornea
• Ciliates


  Single-celled organisms that, at some stage in their life cycle, possess cilia, short hairlike organelles used for locomotion and food gathering
• Cytoplasmic inclusions: Bacteria and other cells

  • Amoeboid
  • Trophozoite
  • Cyst
  • Flagellated form
• Naegleria fowleri


  Considered as the only amoeba that has three morphological forms in its life cycle that infects human